Thombre A G, Himmelstein K J
J Pharm Sci. 1984 Feb;73(2):219-22. doi: 10.1002/jps.2600730219.
The bioavailability of topically applied pilocarpine is poor due to various loss mechanisms that serve to lessen delivery of the drug to the aqueous humor. Precorneal drainage and other routes of loss have been investigated qualitatively as well as quantitatively. The mechanistic models proposed to date suffer from the drawback of being dependent on our understanding of the mechanism of drug transport through the corneal membrane. This report quantifies the initial disposition of topically applied drugs and their availability for systemic and local absorption. The rate constant for the conjunctival absorption is determined and is independent of the mechanism of transcorneal transport.
由于各种损失机制会减少药物向房水的递送，局部应用毛果芸香碱的生物利用度较差。角膜前引流和其他损失途径已得到定性和定量研究。迄今为止提出的机制模型存在依赖于我们对药物透过角膜膜转运机制理解的缺点。本报告对局部应用药物的初始处置及其全身和局部吸收的可用性进行了量化。确定了结膜吸收的速率常数，且该常数与角膜转运机制无关。
